feat(core): 添加IP地址检测服务核心功能

- 实现配置文件加载和解析功能，支持服务器、MMDB数据库和日志配置
- 集成GeoLite2城市数据库查询，提供IP地理位置信息查询服务
- 添加私有IP地址检测逻辑，过滤本地网络地址段
- 构建HTTP路由处理器，返回JSON格式的IP位置信息
- 配置默认启动参数和错误处理机制
- 集成日志系统，记录请求处理过程和错误信息

cmd/checkip/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"checkIP/internal/app"
+	"checkIP/internal/config"
+	"checkIP/internal/mmdb"
+	"fmt"
+
+	"github.com/sirupsen/logrus"
+)
+
+func main() {
+	cfg, err := config.Load("./configs/config.yaml")
+	if err != nil {
+		logrus.WithError(err).Fatal("load config failed")
+	}
+
+	if cfg.Log.Level != "" {
+		level, err := logrus.ParseLevel(cfg.Log.Level)
+		if err != nil {
+			logrus.WithError(err).Fatal("invalid log level")
+		}
+		logrus.SetLevel(level)
+	}
+
+	mmdbReader, err := mmdb.New(cfg.MMDB.FilePath)
+	if err != nil {
+		logrus.WithError(err).Fatal("init mmdb reader failed")
+	}
+
+	router := app.NewRouter(mmdbReader)
+	addr := fmt.Sprintf("%s:%d", cfg.Server.Host, cfg.Server.Port)
+	if err := router.Run(addr); err != nil {
+		logrus.WithError(err).Fatal("http server failed")
+	}
+}

configs/config.yaml

@@ -0,0 +1,9 @@
+server:
+  host: 0.0.0.0
+  port: 8431
+
+mmdb:
+  filePath: ./db/GeoLite2-City.mmdb
+
+log:
+  level: debug

internal/app/router.go

@@ -0,0 +1,52 @@
+package app
+
+import (
+	"net/http"
+
+	"checkIP/internal/mmdb"
+	"checkIP/internal/network"
+
+	"github.com/gin-gonic/gin"
+	"github.com/sirupsen/logrus"
+)
+
+func NewRouter(reader *mmdb.Reader) *gin.Engine {
+	router := gin.New()
+	router.Use(gin.Recovery())
+	router.Use(gin.LoggerWithWriter(logrus.StandardLogger().Out))
+
+	router.GET("/", func(c *gin.Context) {
+		ip := c.ClientIP()
+		if ip == "" {
+			c.String(http.StatusBadRequest, "Invalid IP")
+			return
+		}
+
+		ipInfo := network.GetIPInformation(ip)
+		fields := logrus.Fields{
+			"ip":         ipInfo.IP,
+			"is_private": ipInfo.IsPrivate,
+		}
+		if ipInfo.IsPrivate {
+			fields["private_cidr"] = ipInfo.PrivateCIDR
+		}
+		logrus.WithFields(fields).Info("ip check")
+
+		if ipInfo.IsPrivate {
+			c.String(http.StatusBadRequest, "Invalid IP")
+			return
+		}
+
+		ipLocation, err := reader.QueryIP(ipInfo.IP)
+		if err != nil {
+			logrus.WithError(err).Error("mmdb lookup failed")
+			c.Status(http.StatusInternalServerError)
+			return
+		}
+
+		logrus.WithField("ip_info", ipLocation).Info("mmdb lookup")
+		c.JSON(http.StatusOK, ipLocation)
+	})
+
+	return router
+}

internal/config/config.go

@@ -0,0 +1,39 @@
+package config
+
+import (
+	"fmt"
+	"os"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Config struct {
+	Server ServerConfig `yaml:"server"`
+	MMDB   MMDBConfig   `yaml:"mmdb"`
+	Log    LogConfig    `yaml:"log"`
+}
+
+type ServerConfig struct {
+	Host string `yaml:"host"`
+	Port int    `yaml:"port"`
+}
+
+type MMDBConfig struct {
+	FilePath string `yaml:"filePath"`
+}
+
+type LogConfig struct {
+	Level string `yaml:"level"`
+}
+
+func Load(path string) (Config, error) {
+	var cfg Config
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return cfg, fmt.Errorf("read config: %w", err)
+	}
+	if err := yaml.Unmarshal(data, &cfg); err != nil {
+		return cfg, fmt.Errorf("parse yaml: %w", err)
+	}
+	return cfg, nil
+}

internal/mmdb/reader.go

@@ -0,0 +1,49 @@
+package mmdb
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/IncSW/geoip2"
+)
+
+type IpInfo struct {
+	Ip             string `json:"ip"`
+	CountryIsoCode string `json:"country_iso_code"`
+	CountryName    string `json:"country_name"`
+	City           string `json:"city"`
+	TimeZone       string `json:"time_zone"`
+}
+
+type Reader struct {
+	reader *geoip2.CityReader
+}
+
+func New(filePath string) (*Reader, error) {
+	if filePath == "" {
+		return nil, fmt.Errorf("mmdb file path is empty")
+	}
+	r, err := geoip2.NewCityReaderFromFile(filePath)
+	if err != nil {
+		return nil, fmt.Errorf("open mmdb: %w", err)
+	}
+	return &Reader{reader: r}, nil
+}
+
+func (r *Reader) QueryIP(ip string) (IpInfo, error) {
+	if r == nil || r.reader == nil {
+		return IpInfo{}, fmt.Errorf("mmdb reader not initialized")
+	}
+	record, err := r.reader.Lookup(net.ParseIP(ip))
+	if err != nil {
+		return IpInfo{}, fmt.Errorf("lookup ip: %w", err)
+	}
+	info := IpInfo{
+		Ip:             ip,
+		CountryIsoCode: record.Country.ISOCode,
+		CountryName:    record.Country.Names["en"],
+		City:           record.City.Names["en"],
+		TimeZone:       record.Location.TimeZone,
+	}
+	return info, nil
+}

internal/network/private.go

@@ -0,0 +1,52 @@
+package network
+
+import (
+	"net"
+
+	"github.com/sirupsen/logrus"
+)
+
+type IPInformation struct {
+	IP          string
+	IsPrivate   bool
+	PrivateCIDR string
+}
+
+func GetIPInformation(ip string) IPInformation {
+	ipInfo := IPInformation{
+		IP:          ip,
+		IsPrivate:   false,
+		PrivateCIDR: "",
+	}
+
+	cidrs := []*net.IPNet{
+		parseCIDR("10.0.0.0/8"),
+		parseCIDR("172.16.0.0/12"),
+		parseCIDR("192.168.0.0/16"),
+		parseCIDR("127.0.0.1/16"),
+	}
+
+	ipAddr := net.ParseIP(ip)
+	if ipAddr == nil {
+		logrus.Warn("invalid ip address")
+		return ipInfo
+	}
+
+	for _, cidr := range cidrs {
+		if cidr.Contains(ipAddr) {
+			ipInfo.IsPrivate = true
+			ipInfo.PrivateCIDR = cidr.String()
+			break
+		}
+	}
+
+	return ipInfo
+}
+
+func parseCIDR(cidr string) *net.IPNet {
+	_, ipNet, err := net.ParseCIDR(cidr)
+	if err != nil {
+		panic(err)
+	}
+	return ipNet
+}